The present invention relates to a new and improved apparatus for use with a seat belt for restraining a vehicle occupant.
A known apparatus for use with a seat belt includes a pretensioner assembly which is operable to move a seat belt buckle through a pretensioning stroke to remove slack from the seat belt. At the end of the pretensioning stroke, movement of the buckle is abruptly stopped. When this occurs, inertia of an actuator member in the buckle may tend to move the actuator member and effect operation of the buckle to release a tongue connected with the seat belt. In order to prevent release of the tongue, it has been suggested that a mass be used to apply a force against the actuator member to offset the inertia of the actuator member.